Hydrogen production from methanol steam reforming over Cu–Ti–P oxide catalysts

Cu–Ti–P oxide catalysts, with Cu (1.0 mol%) and P (1.0, 2.0, and 4.0 mol%) incorporated into the framework of Ti(1.0 mol%)O2, were synthesized using a solvothermal method and their potential compatibilities in methanol steam reforming (MSR) were investigated. The scanning electron microscopy (SEM) image of Cu(1)–Ti(1)–P(2) oxide revealed a uniform sheet type, whereas the other two catalysts, Cu(1)–Ti(1)–P(1) and Cu(1)–Ti(1)–P(4), were irregular and non-uniform. Comparative experiments in oxidative MSR were also conducted over a γ-Al2O3 support. The Cu–Ti–P/γ-Al2O3 catalysts provided significantly higher MSR reactivity compared to that without P component, and the tendency was similar in the presence of the γ-Al2O3 support. The main products from steam reforming over the Cu–Ti–P/γ-Al2O3 catalysts were H2, CO, and CO2. The Cu–Ti–P/γ-Al2O3 catalysts also reduced the degree of carbon deposition and improved the H2 product selectivity by facilitating complete oxidation around 600 °C. Herein, we suggest a mechanism in which the P component plays the important role of encouraging the Brønsted acid sites, leading to strong partial oxidation and thermal cracking of methanol to acetaldehyde and CO2, and finally to an increased hydrogen yield and suppressed CO generation.